As the chart below shows, from 1 billion in 1800 the number of people on planet Earth has skyrocketed in the past 50 years and some are projecting 9.3 billion by 2050 and 10 billion by 2100.

Two reasons are behind this rapid growth: substantial reductions in mortality due to widespread health spending and a lagging reduction in fertility rates in developing countries.

The frightening fact is that as the population grows, the population of the Earth is becoming less developed:

In a world population that will go from 3 billion to 7 billion in only half a century, longer lives for everyone and reduced fertility in “more developed regions” – as the UN Population Division terms them – means the bulk of humanity is becoming increasingly “less developed.” In 1950, 68 percent of the world population was accounted for by less developed regions. Today they account for 82 percent and by 2050, the UN projects, will make up 86 percent of the world population. It is expected that between now and 2050 the world population will increase by 2.3 billion. Nearly all (97 percent) of that increase will occur in the less developed regions.

Nigeria, for example, will soon be the world’s fourth most populated country behind India, China and the US. Its current population of 166 million is projected to explode to 402 million by 2050 behind a fertility rate of 7.1 births per woman.

With a world of 10 billion people facing us by the end of this century, the number of formidable challenges are going to snowball. Concerns about falling standards of living, rising health costs, the available food supply and increased environmental degradation are only going to multiply. And of course, where are we going to find the energy resources to help us deal with these challenges at a time when the world is looking at high cost if not reduced oil reserves, reducing reliance on coal, and fears with nuclear energy and natural gas fracking. Will renewable energy sources, on their own, be capable of supplying the energy needs of all 10 billion people? We are currently part of an experiment to find out the answer to that question.